1. Field of the Invention
The present invention relates to a selective cannulation method conducted to a branch section or a collecting section of a lumenal tissue of a living organ, and relates to an endoscopic treatment instrument for use in the aforementioned method.
2. Background Art
Endoscopic retrograde cholangiopancreatography (ERCP) is a conventionally-known diagnostic method for acknowledging in abnormality in a pancreas, a cholecyst, or a bile duct. The ERCP provides X-ray photography by inserting a catheter into the duodenal papilla and subsequently injecting contrast agent directly into a pancreatic duct or a bile duct (see, for example, Japanese Unexamined Patent Application, First Publication No. 2002-272675). In addition, selective insertion of a catheter or an endoscopic treatment instrument is conducted via a duodenal papilla for removing gallstones or for indwelling a stent into a constricture developed in a bile duct. Reliable insertion of endoscopic treatment instruments or the like into the bile duct requires skill since the bile duct and a pancreatic duct have apertures on a common duct through which they communicate with a duodenal papilla.